[Solved] Problems Unmounting (umount2: Device or resource busy)

The process to go through when you’re having trouble unmounting something in Ubuntu.

Most basic command:

sudo umount /mnt/drive

Try to force the unmount with -f flag:

sudo umount -f /mnt/drive

Use lsof or fuser to figure out what PID is making the device busy, and kill it:

sudo lsof | grep /mnt/drive


sudo fuser -c /mnt/drive

lsof and fuser not showing anything? Try:

sudo fuser -vm /mnt/drive

to show the culprit, and

sudo fuser -km /mnt/drive

to kill any and all processes that are busying up the device.

Happy unmounting